Electric terminal



March 18, 1969 T. J. DYKZEUL 3,434,100

ELECTRI G TERMINAL Filed May 22, 1967 WWII INVENTOR. Theodore J. Dykzeul A TTORNEYS United States Patent 3,434,100 ELECTRIC TERMINAL Theodore J. Dykzeul, Rolling Hills, Calif., assignor to Robertshaw Controls Company, Richmond, Va., a corporation of Delaware Filed May 22, 1967, Ser. No. 640,173 US. Cl. 339-196 Int. Cl. H 0lr 33/04 9 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to electric terminals and, in particular, to a terminal constructed and arranged to be compressed between spaced conductors.

In gas burning appliances, it is conventional practice to provide a thermostatic control for normal thermostatic cycling of the gas burner as well as an automatic safety shut-off control including a thermoelectrically controlled magnet. Such magnet is held in its energized position by thermoelectric current produced by a thermocouple disposed in the flame of a pilot gas burner and may be deenergized either by a high limit switch assembled within the normal thermostatic control and connected into the thermoelectric circuit for the holding magnet or by the extinguishment of the pilot flame.

An object of the present invention is to provide an electric terminal of simplified design wherein the switch components are readily assembled and then concealed within a sturdy body member.

Another object is to completely enclose the Wiring for a thermoelectrically controlled magnet assembly, thus protecting the wires from external damage.

Another object of the present invention is to fabricate an electric terminal that is flange-mounted upon an automatic pilot magnet assembly and is secured thereto by a bonding agent, thus facilitating installation and/ or replacement of such magnet assemblies.

Yet another object is to construct a terminal assembly that relies upon a minimum of mechanical contacts.

In accordance with the present invention an electric terminal includes a plug element having metallic, conducting receptacles, a body member formed of insulating material, a plurality of openings in the walls of the body member, a pair of contact blades disposed in spaced relation to each other within the interior of the body member, an insulating strip disposed between the contact blades, the contact blades having a contact part that is disposed in alignment with a certain one of the openings in the walls of the body member, and prong connectors extending upwardly from the contact blade through other of the openings in the walls of the body member whereby the body member can be pressed into electrical contact with the plug element.

Other objects and advantages of the present invention will become apparent from the following description when construed in conjunction with the accompanying drawing wherein:

FIG. 1 is a perspective view of a portion of a control device employing therein an electric terminal constructed in accordance with the principles of this invention, such terminal being shown, for illustrative purposes, prior to securement to the control device;

1 FIG. 2 is a front elevation of the magnet assembly base p ate;

FIG. 3 is a side elevation of the electric terminal of FIG. 1;

FIG. 4 is a bottom plan view of a first body member of the terminal of FIG. 3;

FIG. 5 is a bottom plan view of a second body member of the terminal of FIG. 3;

FIG. 6 is a front elevation of a first contact blade incorporated within the terminal of FIG. 3;

FIG. 7 is a cross section taken along the line 77 of FIG. 6;

FIG. 8 is a front elevation of an insulator plate incorporated within the terminal of FIG. 3;

FIG. 9 is a front elevation of a second contact blade incorporated within the terminal of FIG. 3; and

FIG. 10 is a cross section taken substantially along line 1010 of FIG. 9.

As illustrated in FIG. 1, a preferred embodiment of the present invention is incorporated into a thermostatic control device, indicated generally by reference numeral 10, which thermostatically controls gas flow to gas burner apparatus in a well known manner. Accordingly, for the sake of brevity only those elements of the control device essential to an understanding of the present invention are set forth in this application. The designations of upper, lower, left and right, etc. are adapted for convenience in spatially relating the various components under discus- SlOIl.

Control device 10 includes an inlet port (not shown) for receiving fuel from a gas source supplying same, and an outlet port 12 for discharging the fuel to a pilot burner and main burner (not shown). Mounting shank 14, of which only a lowermost fragmentary portion is shown, is positioned atop device 10 by collar 16. A thermostat, in the form of a conventional rod and tube thermostat (not shown), is disposed within such shank. Screws 18 and 20 secure the collar to the upper surface of control device 10, as viewed in FIG. 1, so that shank 14 can be secured to a gas burning appliance, such as a water heater, with the thermostat extending laterally into the interior of the heater tank for purposes of thermostatic control.

A pair of leads 22 and 24 extends from beneath collar 16 laterally across device to plug 26, which is fabricated from polypropylene or some similar plastic material. A cover (not shown) could readily be provided to enclose leads 22 and 24, and thus protect the leads from external damage. A pair of metallic tubular receptacles 28 and 30 are located within plug 26. Lead 22 is connected to receptacle 28 and lead 24 is connected to receptacle 30, while the opposite ends of leads 22 and 24 are connected to a thermostatic limit switch which is located Within the above mentioned rod and tube thermostat. Plug 26 is located within a shallow recess defined between the upper surface of device 10 and vertical wall 32.

Wall 32 'has a cutout portion in one corner to permit access to the open ends of receptacles 28 and 30 in plug 26. Threaded holes 34 are provided for fastening members to complete the assembly of the control device. A large, centrally located bore 36 accommodates a thermoelectric safety valve assembly, indicated generally by reference character 38.

Valve assembly 38 is of conventional design and, accordingly, only the base 40 with its threaded collar 42 and housing 44 for supporting such assembly within bore 36 are shown. A magnet and its energizing coil (not shown) are disposed within the housing 44, and one end of such energizing coil is connected to a ground lead and its other end is connected to a thermocouple cable assembly, indicated generally at 46. Gasketing material may be positioned between base 40 and wall 32 before joining these members together, and prior to threading thermocouple assembly -46 into engagement with collar 42.

Thermocouple assembly 46 is of standard construction and does not constitute an integral part of the present invention. Assembly 46 comprises a lead 48, outer tubing 50, and insulating material 52 which is formed around the periphery of lead 48 to prevent shorting with the tubing. Lead 48 extends rearwardly through etxernally threaded adaptor nut 54, so that when nut 54 is screwed into engagement with collar 52, the thermocouple as sembly is aligned in operative association with the electric terminal. Such terminal will be described subsequently with detailed reference to FIGS. 3-10.

As illustrated in FIG. 2, magnet assembly base 40 has a pair of ribs 56 and 58 integrally formed with a centrally located collar 42. An angularly disposed lip 60 extends between the ribs, and these members cooperate with the face of base 40 to define a shallow pocket 62 or slot opening into the collar 42. A notch 64 is removed from the upper right hand corner of base 40 to enable the flange mounting and subsequent securement of the electric terminal to base 40. Unthreaded holes 66 and 68 enable fasteners to pass therethrough and engage threaded holes 34 in the main body of control 10.

FIG. 3 illustrates the electric terminal 70 in assembled condition prior to being flange mounted and secured to base 40, while FIGS. 4l0 depict the various components of the terminal in disassembled condition. Terminal 70 includes a two piece plastic body consisting of a rear member 72 with an upper section of reduced dimensions and a front member 74. A pair of contact blades, which terminate in prong-like arms, 76 and 78, respectively, in addition to an insulator blade (not visible in FIG. 3) situated therebet-ween, are retained in fixed position between body members 72 and 74 of terminal 70 when the body members are joined together to form a unitary terminal structure.

Rear member 72, as seen in FIG. 4, has a large circular cutout 80 adjacent to one end. An angularly extending shelf 82 having cylindrical bosses 84 and 86 with interior apertures 88 and 90 is situated at the opposite end of member 72. Such apertures are slightly larger in diameter than the prong-like arms of the contact blades 76 and 78. Accordingly, such prongs protrude beyond the insulating body member and are supported by bosses 84- and 86.

Front member 74 has a circular cutout 92 adjacent to one end, a raised ridge 94 near its midpoint, and a protruding lip section consisting of a short leg 96 and a long leg 98. Referring to FIG. 2, leg 98 is equal in length to the horizontal distance from the upper end of rib 56 to the right hand edge of base 40 whereas leg 96 is equal in length to the vertical distance from the upper end of rib 58 to the upper edge of base 40.

FIGS. 6-10 illustrate the contact blades and insulator blades that are retained between body members 72 and 74 of the electric terminal. For example, FIGS. 6 and 7 show the relationship between a first contact blade and prong-like arm 76. Thus, it is seen that prong 76 is offset at a. slight angle from the body portion 100 of the first contact blade when viewed in front elevation (FIG. 6), and prong 76 extends perpendicularly downwardly from body 100 when viewed in end elevation (FIG. 7). Body portion 100 is deformed at its opposite end to form a shallow, conical depression 102 with an aperture '104 in its lowermost end.

Insulating strip 106 is positioned between the two contact blades to prevent shorting. Such strip has a shallow conical depression 108 with an aperture 110 therein formed proximate one end of the strip. Depression 108 is, however, slightly deeper than depression 102 so that contact blade \100 can be seated upon strip 106.

The relationship between prong 78 and the second contact blade is seen in FIGS. 9 and 10. Prong 78 is offset angularly downward from body portion 112 of the second contact blade when viewed in front elevation (FIG. 9) and extends perpendicularly downwardly therefrom when viewed in end elevation (FIG. 10). Body portion .112 is deformed at its opposite end to form a relatively deep, conical depression 114 with an aperture 116 in its lowermost end. The upper reaches of depression 114 extend slightly above the horizontal plane of body portion 112, and enables depression 108 of insulation strip 106 to be seated therein to align the contact blades and the insulation strip within the terminal body.

The above described components are readily assembled into an operative relationship in the following manner. Prong 76 of blade 100 is pressed through aperture 88 in boss 84 of body member 72 and depression 102 is aligned with cutout 80. Insulator strip 106 is then placed into position adjacent to blade 100, and second contact blade 112 is then pressed through aperture 90 in boss 86. The second body member 74 is then secured to body member 72, by a conventional adhesive agent to form a unitary housing.

The assembled terminal is then flange mounted upon base 40 by placing lip 96 in contact with rib 58 of base 40 and lip 98 in contact with rib 56. With the lips in this position, terminal is secured to base 40 by a potting process or by an adhesive agent. Thus, the apertures and 92 and depressions .102, 108 and 1114 at the lower end of the assembled components of the terminal will extend through pocket 62 into alignment with assembly 46. Since depressions 102, 108 and 114 become progressively deeper, the pair of blades and strip 106 are aligned by a nesting process. Ridge 94 on connector body member 74 assists in the proper orientation of the terminal in relation to the thermocouple assembly, so that the head of assembly 46 bears upon the depressions in the contact blades and maintains positive electrical contact. Prongs 76 and 78 are then pressed into engagement with receptacles 28 and 30 in plug 26 to complete the holding circuit for thermoelectric magnet assembly 44. Base 40 is then secured in abutting relationship to wall 32 by conventional fasteners that pass through holes 66 and 68 and are threaded into holes 34.

Whenever servicing is required, base 40 with terminal 70 secured thereto, is disengaged as a unit from control 10 and a new subassembly is substituted. Thus, servicing of control 10 is simplified with attendant cost reductions.

Inasmuch as the preferred embodiment of the present invention is subject to many variations and changes in details without departing from the principles of the present invention, it is intended that all matter contained in the foregoing description or shown on the accompanying drawing, shall be interpreted as illustrative in nature and not in a limiting sense.

What is claimed is:

1. An electric terminal assembly comprising:

a plug element having conductor means therein,

a body member formed of insulating material,

means defining a plurality of openings through the walls of said body member,

a pair of contact blades extending in the same direction and having planar surfaces disposed in overlying spaced relation to each other within said body member,

insulator means disposed between said blades to prevent electrical contact therebetween,

said blades having a contact part that is disposed in alignment with a certain one of said openings, and

connector means formed on said blades and extending outwardly away from the planar surfaces of said blades through other of said openings whereby said body member can be pressed into electrical contact with said plug element.

2. The combination as defined in claim 1 wherein said connector means comprises a prong located at the end of said contact blade furthest from said contact part.

3. The combination as defined in claim 1 wherein said body member has a raised lip, said lip being adapted to .flangemount said body member.

4. The combination as defined in claim 1 wherein said body member is formed of two separate members joined together as an integral unit, said first member comprising a planar body with an opening at one end and a raised shelf portion at the opposite end.

5. The combination as defined in claim 4 wherein said shelf has bosses mounted thereon, openings extending through said bosses to permit said connector means to extend therethrough.

6. The combination as defined in claim 4 wherein said second member comprises a planar body with an opening at one end and a lip at the opposite end thereof, said lip extending forwardly of said plate member.

7. The combination as defined in claim 1 wherein said contact part comprises a conical deformation, the deformation on one of said blades being slightly deeper than the deformation on the second blade for nesting engagement.

8. The combination as defined in claim 7 wherein said insulation means comprises a plastic strip, said strip having a contact part that is aligned with the deformations on said contact blades.

9. The combination as defined in claim 1 wherein said conductor means in the plug element comprises a pair of spaced metallic receptacles.

References Cited UNITED STATES PATENTS 1,846,251 2/1932 Donahue 339- 2,915,736 12/1959 Smith et al 339-196 X 2,915,737 12/1959 Morse 339'-195 MARVIN A. CHAMPION, Primary Examiner.

JOHN R. MOSES, Assistant Examiner. 

